package com.web.handler;

import lombok.extern.slf4j.Slf4j;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;

import javax.servlet.*;
import java.io.IOException;

/**
 * @author xukk
 * @date 2017/6/5
 */
@Slf4j
public class MyFilterSecurityInterceptor extends AbstractSecurityInterceptor implements Filter {

    private SecurityMetadataSourceService securityMetadataSourceService;

    public SecurityMetadataSourceService getSecurityMetadataSourceService() {
        return securityMetadataSourceService;
    }

    public void setSecurityMetadataSourceService(SecurityMetadataSourceService securityMetadataSourceService) {
        this.securityMetadataSourceService = securityMetadataSourceService;
    }

    /**
     * 登陆后，每次访问资源都通过这个拦截器拦截
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        FilterInvocation fi = new FilterInvocation(request, response, chain);
        invoke(fi);
    }

    @Override
    public Class<? extends Object> getSecureObjectClass() {
        return FilterInvocation.class;
    }

    public void invoke(FilterInvocation fi) throws IOException, ServletException {
        //fi里面有一个被拦截的url
        //里面调用MyInvocationSecurityMetadataSource的getAttributes(Object object)这个方法获取fi对应的所有权限
        //再调用MyAccessDecisionManager的decide方法来校验用户的权限是否足够
        InterceptorStatusToken token = super.beforeInvocation(fi);
        try {
            //执行下一个拦截器
            fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
        } finally {
            super.afterInvocation(token, null);
        }
    }

    @Override
    public SecurityMetadataSource obtainSecurityMetadataSource() {
        return this.securityMetadataSourceService;
    }

    @Override
    public void destroy() {

    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {

    }
}
